The ban is set to come into force in 2019 for newer ships and in 2021 for older vessels. The ban is chiefly directed towards the large ships that cruise the Gulf of Finland in the summer.

The Baltic Marine Environment Protection Commission, HELCOM, works to protect the marine environment of the Baltic Sea, and has been campaigning for the sea-dumping ban for the past decade.

Image: theportandthecity.wordpress.com

Hermanni Backer, the professional secretary of HELCOM's maritime, response and fish departments, said that once the measure goes into effect, the Baltic will be the world's first sea region which outright bans passenger vessels' commonplace sewage-dumping practices. Backer said:

"This is actually very important. We have gotten a concrete decision and that's always positive. Now the most important thing is to get all countries [in the region] onboard. There is a slight risk that Russia would not participate."

Nearly 300 international cruise ships visit Helsinki every year, and with them arrives tonnes of dirty, untreated wastewater.

HELCOM estimates that the city's harbours host some seven million tourist overnight stays via the visiting cruise ships – which adds up to a lot of sewage. But those days will be over relatively soon. Backer added:

"I really think this is something very positive and we have are very pleased about this. We have to make sure that industry and harbours continue with this progress and implement this successfully for all parties involved".

Even though there is a transition period five years for vessels which are already in use, Backer said that the decision is good for the Baltic.

"It's something that we have all been waiting for and it's wonderful that it will finally happen."